Air-brake system and automatic valve.



PATENTED FEB. 6, mos.

F. B. COREY.

AIR BRAKE SYSTEM AND AUTOMATIC VALVE.

LPPLIGATIOR FILED SEPT. 16. 1904.

lnven'bom Fred. B. Coreg.

Witnesses: Z7

UNITED STATES PATENT OFFICE.

FRED B. COREY, OF SGHENEUTADY, NEW YORK, ASSIGNGR TO GENERAL ELECTRIC COMPANY, A CORPORATION OFNEW YORK.

AIR-BRAKE SYSTEM AND AUTOMATiO VALVE.

Specification of Letters Patent.

Patented-Feb. a, 19cc.

Application filed September 16,1904. Serial No. 224,651. V

tages of the automatic air-brake system and m addition certain other advantages not heretofore obtained, including means for obtaining a graduated application of the brakes and an operation of t e amount of air.

In the automatic system as ordinarily ems ployed, in which the main reservoir is carried at one end of the train and air for the brakes is transmitted from the main reservoir through the train-pipe to the 'severalauxiliary reservoirs, the train-pipe for long trains must be of considerable size, and consequently a eat'amount of air is wasted in raising an lower-in the train-pipe ressure' in the o ration of t e brakes. On t e other 'hand,w on each car is provided with its own source of coin ressed air, the reservoirs on the several cars emg connected to a common train-pipe, it is BGGGSSHJYID provide more or less complicated means r synchronizing the overnors for the several compressors in or- 561' to distribute the work properly among the com ressors. By my invention-I provide eac pressed air, but maintain the braking systems of the several cars independent of each other,

so that no synchronizin means for the governors is required, and v 4 pipe extending through c tram by, means of which an. automatlc valve on each ear is -controlled,so as to apply and release the brakes. Since this control-pipe does not carrysair forthebrakes, but merely operates an automatic or relay valve on each car, it maybe made very small ascompared with the usual train-pipe, and consequentl a great economy of air in braking results. urthermore, I so arrange the automatic valves that-they return automatically to la posi-.

tion whenever the pressure in the bra e-c linder bears a certain relation to that in t is train-pipe. Consequently by reducing the brakes with a very small position whenever the pressure in the brake- Ibeen leftin release position -that is with the car with its'ow'n source of com; l

rovide a control-' pressure in the train-pipe step by ste the pressure in thcbrake-cylinder is raise step y step, so as to obtain a graduated series of increases and reductions of braking force withoiit an intermediate total release, as is required in an automatic system.

My invention, then, in one aspect consists in the combination witha train of cars of a source of compressed air on each car, a control-pipe extending through the train, and an .automaticvalve on each car responsive tovariations of pressure in the control-pi e and ar-' ranged to connect the brake-cylin er on the car to reservoir to apply the brakes or to atrnosphere to release t e brakes, the valve being arranged to return automatically to. lap

consists in a com considered, my invention matron, as abovestated,

provided with automatic valves responding differentially to the pressures in the brake cylinders and control-pipe.

Another feature of my invention consists in providing two reservoirs on each car "ch ed from the same compressor, but separate from each other by a check-valve one of the reservoirs being connected through the motorxnans valve to the controi pipe and the other being connected tothe automatic aive. 'With arrangement it is evident t at if the train breaks a art, exhausting the con trol-pipe, and if t e motormans valve has reservoir connected to the centre -pi e, so that the reservoir itself is exhausted the check-valve between the two reservoirs will maintain the ressure in the second reservoir so that it w' be available for applying the brakes. l Another feature of my invention consists in the novel construction and arrangement of the automatic valve whereby the desired differential actionis obtained.

Other features of my invention will appear in the following specification and accompanydrawings, in whichgore 1 shows diagrammatically the airhrake system of one car of a train arranged in accordance with my invention, and Fi 2 shows a sectional view of the automatic valve.

' 1, Crepresen ts the compressor driven by the electric motor M. The governor (not shown) for the compressor is arranged to respond to variations in the pressure of reservoir R, connected to the compressor, and to control the circuit of the motor Min the usual end,to the usual motormans valve V, to

i which is also connected the train-pipe t. The

lnotormans valves are arranged n connect the train-pipe t to reservoir R m io atmosphcre sodls to raise and lower tlu iressure in the train-pipe '1. Connected ti the train pipe t, through the connection t, s an automatic valve A, which is also ",onnected throughthe pipe 1" to the second reexrvoir R, which is connected to the first reservoir R througlra check-valve v. This check-valve is so arranged as to permit a free flow or air from reservoir R to reservoir R, but prevents a flow in the op osite direction, the purpose being, as hereto ore explained, to prevent the lowering of pressure in reservoir R if reservoir R is exhausted by a breakage of the train-pipe. The automatic valve A controls theconnection, as will be hereinafter explained,.between the pipe 1", leading to reservoir R ,ygin'd the pipe I), leadin to the brake B. Ftrain-pipe'is provided at each end with-couplings, as shown, for connection with the other cars of the train, it being understood 1 thatthe equipment of each car is a duplicai shown in Fig. 2.

tion of that snown in Fig. 1.

The construction of the automatic valve A The conncctions'io the reservoir-pipe, 'the control-pipe, and the brake-pipe are indicated by the letters 1-, t, and b. The connection t to the controlpipe opens into a chamber between two rigid y-connected diaphra ms d and, d,.thelatter being of greater effective area than the fori'nelr. The smaller diaphragm (l is subjected on its outer side to the brake-cylinder pressurej't'o which it is connected through the passage and the pipe com'iection bi The diaphragm d is connected on its outer side to atmosphere through the hamber 11 and a port 12, but issubjccted to the pressure of the piston 7, which is pressed against the diaphragm ll the compression-s n:n 9 1 and 6 re )rcsent two spring-pressed pllot wa ves, w iich are normallv held seated, as shown, by springs, but one of which is raised from itsseat when dia iilu'agms d and it move in one direction or the other. \Vhen the diaphragms are. moved toward the left, the raising of pilot-valve 1 connects chamber 2 to brake-cvlinder through passage 15 and pipe b. The chamber 2 is closed at the left-hand end by the piston 25, butis connected through "a restricted passage 4 111 this piston to cham her 5 on the left of the piston, into which nlKilS'illC (flllnti'llull to the reservoir-pipe.

I ing to atmosphere.

The piston 3 carries a valve 6, which normally closes a port 19, loading to the brakecylinder pipe connection I). The. other pilotvalve 8 when raised from its seat establishes a connection from chamber Hi to chamber H and thence through port 12 to atmosphere. Chamber i0 is cl scd at its right-hand end by the piston 13, whi h is pressed into the position shown by the spring l t. (hamber 10 is connected through a restricted passage in piston 13 with the chamber to, which is in conncctionn'ith the brake-pipe connection I) through the passar' iii. he piston 13 carries the valve 17, hic when thepiston is in the position shown closes the passage 18, l adlhe several parts of the valve are thus shown in lap position.

The operation is then as follows: With the several parts of the auxiliary valve in the position shown if it is desired to apply the brakes thepressure in the control-pipe is reduced. The reduction of pressure between the diaphragms d and d allows the spring 9 to move the diaphragms toward the left, so as to raise pilot-valve 1 from its seat. Chamber 2 is consequently connected to bri li -cylinder through passages 15 and pipe connection I), and since the brake-cylinder is at :1 tinospheric pressure, the brakes being re- ]er.-ed, the chamber 2 is exhausted. The restricted passage 4 in piston 3 is not sutlicicnt to maintain an equality of pressure on its opposite sides, and consequently the reservoirpressure in chamber 5 pushes piston 23 to the right against the pressure of spring 21, moving valve 6, so as to open portv l9. 1 This connects the reservoir-pipe connection 7" to the brake-pipe connection I) through chamber 5, and consequently the pressure in the brakecylindcr is raised and an application of the bralies is secured. As the brie-pressure rises the pressure is raised on the outer side of diaphragm 0! until a point is reached at which a pressure of spring 9 on the outer side of diaphragm cl is balanced, so that the dia; phragms are moved back to lap position, as shown, closing pilot valve 1. When this valve is closed, the )ressure in chamber 2 is quickly equalized with that of chamber 5 by means of'tho passage 4, so that. spring 21 is allowed to push piston 3 back into position shown, breaking the connection between pipes 1" and b. If it is desired to increase the brake-pressure, the pressure in the control-pipe t is further reduced, and the operation that has just been described is repeated. In this manner'a graduated app ication of the brakes may be obtained. Now if it is desired partlv'to release the brakes the pressure in the control-pipe is raised a certain amount. This increase of pressure on the inner side of diaphragm d overpowers s ring 9 and moves the piston 7, so as to lift va va 8 from its seat. By this means chamber 10 is connected with chamber and thence through port 12-to 1 atmosphere. The piston 13 is thus subjected to atmospheric pressure on one side, while on the other side it is subjected to the brake oylindercpressure, and thepassage 20 is too restricte to allow of an equalization of the pressures. The brake-cylinder )ressure consequently moves piston 13 to the left, conipressmg spring 14 and moving valve 17. to uncover passage 18. The brake cylinder is consequently connected to atmos here through p1 e connection I), passa e15,c aniber 16, an passage 18. The bra e-eylinder pressure is consequently reduced until the pressureon the outer side of diaphragm d alls a sufficient amount to allow spring 9 to push the diaphragms back into ositi'on shown. The valveS is then seated, t e pressures on vop osite sides of' piston 13 are quickly equa ized by means of passage 20, and spun 14 pushes the piston back into the position s own, moving valve 17 to closepasea c 18; Further exhaust from thebrakecy 'nder is thus prevented. By further in= creasing the pressure 'in the control-pi c more air is released from the brake-cylin er, and thus a graduated release is obtained. It will be seen that the train-pipe ressure exerts a resultant force on the diapliragms equal to the pressure multiplied by the difierence in area between the two diaphragms and that the brake-cylinder pressure exerts atoms in the same direction e ual to the brake-c linder Ipressure multiplied by the area 0 the sme er diaphragmd. urthermere, the valve automatically moves to the lap positien whenever the sum of these two forces is equal to the constant op osingressure exerted by the s ring 9. ff the iiference in area. betweentiie two dia hra ms were equal to the area lief the sme er 'iaphragm, the train pipe and brake-cylinder pressure would exert equal effective forces per pound of pressure, and the valve would move to the lap position whenever sum of the train-pipe pres;

sure and. the brake-cylinder pressure was equal to a constant, and a variation in the train-pipe pressure would produce an exactly equal variation in the bridge-pipe pressure. By making the difference in area between the two diaphra ms greater than the area of the smaller diaphragm it is evident that the train-pipe pressure exerts a greater effective force per pound than the brake-cylinder pressure and that a given variation in train-pipe pressure will produce a greater variation in the brake-cylinder pressure. Consequently in order to vary the brake-cylinder pressure from zero to full-reservoir pressure it is not necessary to reduce the train-pipe pressure to zero; but a reduction over a much smaller range is sufficient. Thus the amount of air required for raising and lowering the trainpipe pressure is reduced and the efficiency of the system still further increased.

Obviously other arrangements of die.

ering the pressure between the. two diapliragins d and d, it is-evident that it me be made much smaller than in s stems in w 'ch it must carry air for the rake-cylinders. Consequently the amount of air required to raise and lower the pressure of the controlipe is very small. All the cars are entirely independent of each other as regards their air-brake systems, exce t for the automatic valves, so that no sync ronizing apparatus is required for the governors of the several reservoirs. Q

The connection and arrangement of parts may be greatly altered and other forms of automatic valves may be emplo ed, if desired, and I aim in the appende claims to cover all modifications which are within the see c of my invention.

l llhat I claim as new, and desire to, secure by Letters Patent of the United Stat es, is-

1. In combination with a train of cars, an

' independent source of compressed air on each car, a control-pipe extending through the train, and an automatic valve on each car responsive to variations in the pressures both in the control-pipe and in the brake-cylinder, and adapted to connect the brake-cylinder to the source of pressure or to atmosphere.

2. In combination with a train of cars, an independent source of compressed air on each car, a controlpipe extending through the train, and an automatic valve on each car connected to said control-pipe and adapted to connect brakerylinder to the source of pressure or to atmosphere, said valve being arranged to return to lap position when the ressures in controlipe and brakecylinder ear a predetermine ,relation to each other.

3. In a train of cars, an independent source of compressed air on each car, a control-pipe extending through the train, an automatic valve on each car responsive tOYQIlfitlODS of the pressures in both the control-p: e and the brake-cylinder and adapted to esta lish connections for applying and releasing the brakes, and means for raising and lowering the pressure in the control-pipe.

4. 111 a train of cars, an independent source of com )rcsscd air on each car, a controlpipe extending through the train, an automatic valve on eachcarcoinprisin a movable mem: her and. a valve cmitrollcd thereby' adapted to establish connections for applying and releasing the brakes, means for impressing on said member two forces tending to move it in the same direction and proportional respectively to the pressures in the control-pipe and in the brake-cylinder, means for impressing on said member a substantially constant opposing foree and means for raising and lowering the pressure in the control-pipe.

5. In a train of cars, an independent source of compressed air on each car comprising two reservoirs, a control-pipe extending through the tram, a manually-controlled valve. connecting one of said reservoirs to said controlpipe, an automatic valve connected to the control-pipe and ada ted to connectbrakecylinder to ti? secon reservoir or to atmossphere,' and n'si-ans for preventing a flow of air from the second to the first reservoir.

6. In a train of cars,an independent source of compressed air on each ear comprising two reservoirs, a control-pipe extending through J the tram, a manually-controlled valve connecting one of said reservoirs to said controlpipe, an automatic valve connected to the control-pipe and ada ted to connect brakecylinder to the see on reservoir or to atmosphere, and a check-valvein erted in the connection between the twores rvoirs.

7. Ina train of cars, a control-pipe extendmg through thetrain, a movable member responsive to variations in pressure in both the control-pipe and the brake-cylinder, two relay-valves arranged l beaoerated respectivcly by the movement of aid inemher in one direction or the other, and two valves controlled by said relays and adapted and arranged to establish connections respectively for applying and for releasing the brakes.

8. In an air-brake system, a control-pipe 40 extending through the train, two rigidly-con nected diaphragms, connections from the brake-cylinder to one side of one diaphragm, connections from the control-pipe to the cor responding side of the other diaphragm, means for impressing a substantially constant opposing force on said di'aphragms, two relays arranged to be operated respectively by. the movement of said diaphragms in one direction or the other, and twovalves controlled so by said relays and adapted and arranged re-- speetively to establish connections for applying and for releasing the brakes.

9. 1n an nir-bral e system, an independent source of compressed air on each car, a control- )ipe extending through the train, two rigidly connected diaphragms, connections from brake-cylinder to one side of one of said diaphragms from said control-pipe to the corresponding side of the other diaphragm,

.means for impressing a suhstantnfi w constant opposing force on said diaphra ms, tvvo rein volves arranged to he op= rate respectively by the movement of said diaphra ms in one direction or the other, and two va ves controlled by said relays and, arranged respectively to connect brake-cylinder to said source of pressure and to atmosphere.

' In witness whereof I have hereunto set my hand this 14th day of September, 1904.

' FRED B. COREY.

Witnesses BENJAMIN HULL,

HELEN Onroun. 

